The Effect of Halothane on the Electroencephalogram of the Cat

ARIOUS workers have attempted to reV late the depth of halothane anesthesia to the electrical activity of the brain as recorded on the electroencephalogram (EEG) . Most patients received some form of premedication, as well as halothane combined with nitrous oxide. Given and associates' reported a correlation between the various types of EEG patterns and the inhaled halothane concentrations. Robson and Sheridan? found EEG changes which could be related to the concentration of halothane in the blood. Gain and Paletz3 and Burnap and coworkers,-l however, concluded that the EEG pattern could not be related to the clinical signs of different depths of anesthesia in patients. DArcy and Payne5 also found no direct relationship between the EEG and the clinical level of anesthesia in man, holding, as did Bromage,o that the EEG pattern could be more closely related to the blood pressure.